Guide assembly for a missile

ABSTRACT

A missile includes a missile body and a guide assembly mounted on the missile body. The guide assembly has a plurality of pivots and a plurality of vanes mounted on respective pivots for a swinging motion between a folded position of rest and a deployed flight position. The vanes are arranged for free pivotal motion during flight in response to forces acting thereon to determine the flight position. Abutments limit the flight position of the vanes to a maximum angle between the length dimension of the vanes and the longitudinal axis of the missile body. The maximum angle is greater than 90°.

CROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority of German Application No.199 59 357.4 filed Dec. 9, 1999, which is incorporated herein byreference,

BACKGROUND OF THE INVENTION

[0002] This invention relates to a missile and particularly concerns aguide assembly therefor. The guide assembly includes vanes which have aninwardly pivoted, folded position of rest and an outwardly pivoted,deployed state which they assume in flight during which the missilerotates about its longitudinal axis.

[0003] Missiles which have foldable stabilizing guide assemblies andwhich, for example, by virtue of the position of the vanes, rotate aboutthe longitudinal missile axis (compensating twist) during flight arewell known. To obtain a defined position of the vanes along the entireflight path, in the known missiles the vanes are blocked (immobilized)by a locking device in their outwardly pivoted, deployed end position.

[0004] It is, among others, a disadvantage of the above-outlined guideassemblies that during flight the forces exerted on the vanes lead tovarying mechanical stresses to which the vane locking mechanisms areexposed. Such changing mechanical stresses often result in jars andvibrations to the entire missile which, for example, when sound sensorsare used, may lead to a defective operation of fuzes of high-explosiveprojectiles.

SUMMARY OF THE INVENTION

[0005] It is an object of the invention to provide an improved missileguide assembly of the above-outlined type whose vanes assume in thedeployed state an aerodynamically favorable position without the forcesexerted thereon (forces derived from air streams, centrifugal forces andmass inertia of the vanes) causing jars of the missile.

[0006] This object and others to become apparent as the specificationprogresses, are accomplished by the invention, according to which,briefly stated, the missile includes a missile body and a guide assemblymounted on the missile body. The guide assembly has a plurality ofpivots and a plurality of vanes mounted on respective pivots for aswinging motion between a folded position of rest and a deployed flightposition. The vanes are arranged for free pivotal motion during flightin response to forces acting thereon to determine the flight position.Abutments limit the flight position of the vanes to a maximum angledefined between the length dimension of the vanes and the longitudinalaxis of the missile body. The maximum angle is greater than 90°.

[0007] The invention is based essentially on the principle to provide adetermined, but unblocked (that is, not locked or immobilized) deployedstate of the vanes during flight. Thus, the vanes, after the missileleaves the weapon tube, are pressed by the initially very high opposingair stream forces into a rearward end position defined by an abutmentand subsequently, the vanes are pivoted forward into a frontal endposition which is determined by an equilibrium of the forces affectingthe vanes during flight. In the state of equilibrium the forces derivedfrom the air stream push the vanes rearwardly while the mass inertiaforces pull the vanes forwardly since the remainder of the missile isbraked to a significantly greater extent than the vanes In any event,the forces derived from the air streams are generally greater than themass inertia forces, but as a rotation of the missile about itslongitudinal axis starts, centrifugal forces generate a torque whichalso effects a forward pivotal motion of the vanes. Although thecentrifugal force continuously increases during the flight of themissile, its axial component decreases as the vanes pivot forward. As aresult, a torque equilibrium occurs where the angle α representing theangle between the length dimension of the vane and the longitudinal axisof the missile is generally greater than 90°.

[0008] The jars which may be caused by the impact of the vanes on theirrespective abutment do not lead to an unintended fuze activation becausethe fuze is armed only when the missile is at a certain distance fromthe firing device (muzzle area safety).

BRIEF DESCRIPTION OF THE DRAWING

[0009] The sole FIGURE is a fragmentary, partially sectional axial viewof a missile illustrating a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0010] Turning to the FIGURE, a guide assembly 2 is mounted on therearward end of a missile body 1 of a missile M. The guide assembly 2has a plurality of vanes 3 and 4 whose forwardly oriented edges areconventionally sharpened for causing the missile body 1 to rotate aboutits longitudinal axis 5.

[0011] The vanes 3 and 4 are pivotal about an axis of a pivot 6 from afolded position of rest (shown in dotted lines for the vane 3) into anoutwardly pivoted deployed flight position. For limiting the pivotaldisplacement caused by initially very substantial air stream forces, thevanes 3, 4 are, with respect to the respective pivot 6, in a laterallydisplaced position so that after they reach a maximum angular positionα_(m) of, for example 120°, they abut with their underside 10 against arearward region 11 of the missile body 1. Such a deployed flightposition is shown in the FIGURE in solid lines for the vane 3.

[0012] As the missile continues its flight, the vanes 3, 4 pivot forwardinto a frontal end position which results from an equilibrium of theforces to which the vane is exposed during flight, Thus, the force 7derived from the air stream pushes the vanes 3 and 4 rearwardly whereasthe force 8 derived from the mass inertia and the centrifugal force 9urge the vanes 3 and 4 to pivot forwardly. The vane 4 is shown in theFIGURE in its aerodynamic position of equilibrium. The angular positionα is, for example, 105°.

[0013] It is to be understood that the invention is not limited to theabove-described embodiment. Thus, for example, the abutment which limitsthe vanes in their outwardly pivoted (deployed) flight position may beeffected by separately provided abutment elements mounted on therearward portion of the missile body 1. The maximum angular position thevanes assume in case of force equilibrium may be greater or lesser than120°; in any event, the maximum angular position of the vanes α_(m) mustbe greater than the angular position α which the vanes assume in thestate of force equilibrium.

[0014] It will be understood that the above description of the presentinvention is susceptible to various modifications, changes andadaptations, and the same are intended to be comprehended within themeaning and range of equivalents of the appended claims.

What is claimed is:
 1. A missile comprising (a) a missile body having alongitudinal axis and (b) a guide assembly mounted on said missile body;said guide assembly including (1) a plurality of pivots; (2) a pluralityof vanes mounted on respective said pivots for a swinging motion betweena folded position of rest and a deployed flight position; each said vanehaving a length dimension; said vanes being arranged for free pivotalmotion during flight in response to forces acting thereon to determinesaid flight position; and (3) abutments limiting said flight position ofsaid vanes to a maximum angle between said length dimension and saidlongitudinal axis; said maximum angle being greater than 90°.
 2. Themissile as defined in claim 1 , wherein said abutments limit saidmaximum angle to 120°.